"They vote with their CPU power, expressing their acceptance of valid blocks by working on extending them and rejecting invalid blocks by refusing to work on them. Any needed rules and incentives can be enforced with this consensus mechanism."
- 'Bitcoin: A Peer-to-Peer Electronic Cash System', Satoshi Nakamoto
The words of Satoshi. Do you believe we should follow it like a religion?
No. At least not just because they are The Words Of Satoshi. But it does concisely explain how Bitcoin actually operates. No matter how much bloviating is directed to the incorrect impression that non-mining entities have any enforcement power over the chain consensus, the design decision of the miners determining the rules is unchanged. As it should.
But that is not the case on how Bitcoin operates today.
You are incorrect. It is exactly how bitcoin operates today.
Hypothetical situation, what if the miners disagree with the economic majority in activating something and the economic majority announces that it will activate and enforce it themselves and take the risk of a chain split?
In such a case, it would be a Mexican standoff until one or the other groups capitulates. There is no a priori way to determine which group would cave. For while it is true that a chain that nobody wants (as if it would be nobody) is worthless, similarly a chain that cannot be traded upon is also worthless.
But a more important question to ask would be why it is that you think that non-mining, validating entities -- the most Sybil-able group in the ecosystem -- has anything to do whatsoever with economic power?
On one side, we have a bunch of neck beards marshalling an army of raspberry pis. On the other side we have a wealth of industry tycoons controlling a multi billion dollar investment in specialized infrastructure. And additional racks and racks of servers dedicated to the validation function. Which of these two groups do you seriously represents the economic majority?
Again, despite your delusion, non-mining validators have fuck-all to do with consensus.
Or what if the miners want to enforce something and the non-mining nodes do not follow?
They will. An investment in an overwhelming number of validators is a rounding error to the miners.
(grammatical edits)